Tool mandrel anti-derotation tool for wellhead pre-connection

Abstract

The application relates to the technical field of underwater wellhead equipment, and particularly discloses a tool spindle anti-offset tool for wellhead pre-connection, which comprises a righting structure and an anti-falling structure. The righting structure is detachably arranged between the end face of a wellhead casing and the outer circumferential surface of a tool spindle penetrating through the wellhead casing. The outer end of the righting structure is adapted to abut against the end pipe body of the wellhead casing, and the inner end is adapted to abut against the outer circumferential surface of the tool spindle penetrating through the casing, so that the tool spindle is limited in the circumferential direction and is prevented from being offset in the radial direction. The anti-falling structure is used for keeping the righting structure in a fixed state of limiting the tool spindle. The tool spindle anti-offset tool for wellhead pre-connection provided by the embodiment of the application can realize the anti-offset effect of the tool spindle during wellhead pre-connection by abutting the end pipe body of the wellhead casing and the outer circumferential surface of the tool spindle at the two ends of the righting structure.

Description

Technical Field

[0001] This invention relates to the field of underwater wellhead equipment technology, and in particular to a tool mandrel anti-offset tool for wellhead pre-connection. Background Technology

[0002] In offshore oil and gas exploration and development, subsea wellhead systems are crucial equipment, serving to stabilize the wellbore and support subsequent production equipment. The high-pressure wellhead nozzle is a key component of the subsea wellhead system. During offshore platform drilling, a 3-4 meter short section is welded to the lower part of the high-pressure wellhead nozzle, and the entire component weighs 5-6 tons. During drilling, it is repeatedly changed from a horizontal to a vertical position or vice versa. For safety reasons, a simple tool to prevent tool mandrel misalignment during wellhead pre-connection needs to be designed to protect the tool mandrel and reduce the impact on the tool seal. Summary of the Invention

[0003] To address the aforementioned problems, the present invention aims to provide a tool mandrel anti-offset tool for wellhead pre-connection, which aims to achieve an anti-offset effect on the tool mandrel during wellhead pre-connection by having the two ends of the straightening structure abut against the end pipe of the wellhead casing and the outer circumferential surface of the tool mandrel, respectively.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A tool mandrel anti-offset tool for wellhead pre-connection includes: a straightening structure and an anti-drop structure. The straightening structure is detachably disposed between the end face of the wellhead casing and the outer peripheral surface of the tool mandrel passing through the wellhead casing. The outer end of the straightening structure is adapted to abut against the end body of the wellhead casing, and the inner end is adapted to abut against the outer peripheral surface of the tool mandrel passing through the casing, so as to limit the tool mandrel in the circumferential direction and prevent it from deviating radially. The anti-drop structure is used to keep the straightening structure in a fixed state that limits the tool mandrel.

[0006] According to some embodiments of the present invention, the straightening structure is configured as a straightening ring, the inner end of the straightening ring being configured as an inner ring body abutting against the outer circumferential surface of the tool mandrel, and the outer end of the straightening ring and the end cylinder of the wellhead casing being configured as a stepped end face and a straight cylinder respectively to achieve engagement.

[0007] According to some embodiments of the present invention, the end tube of the wellhead casing is provided as a straight cylinder; the outer end of the centralizing ring is provided as a stepped end face adapted to engage with the end tube of the wellhead casing, the stepped end face including a first stepped portion adapted to abut against the inner wall surface of the wellhead casing, and a second stepped portion adapted to abut against the end face of the wellhead casing.

[0008] According to some embodiments of the present invention, the straightening ring includes a first part and a second part located on opposite sides of the tool spindle, the inner ends of the first part and the inner ends of the second part are spliced ​​together to form the inner ring body, and the outer ends are provided with the stepped end face.

[0009] According to some embodiments of the present invention, the length of the first stepped portion along the axial direction of the wellhead casing is greater than the length of the second stepped portion along the axial direction of the wellhead casing.

[0010] According to some embodiments of the present invention, the inner ends of the first part and the second part are configured as semicircular rings adapted to engage with the outer peripheral surface of the tool mandrel, or have two abutting planes capable of forming an included angle, the included angle being directed toward the outer peripheral surface of the tool mandrel and selected from the range [20°, 160°].

[0011] According to some embodiments of the present invention, the first part and the second part are symmetrically arranged, and each part is provided with two protruding ends extending outward at intervals. The outer end of the protruding end is provided with the stepped end face, and the four protruding ends are distributed at 90-degree intervals in pairs along the circumference of the inner ring body.

[0012] According to some embodiments of the present invention, the anti-drop structure is detachably mounted on the tool mandrel on the side of the straightening structure opposite to the wellhead casing, for axially abutting and limiting the straightening structure on the tool mandrel.

[0013] According to some embodiments of the present invention, the anti-fall structure includes two interlocking blocks, which are detachably mounted on the tool mandrel on the side of the straightening structure opposite to the wellhead casing by bolts.

[0014] According to some embodiments of the present invention, the middle part of the adjacent sides of the two stops is provided as an arc-shaped surface that adapts to the outer peripheral surface of the tool spindle, and corresponding mounting through holes are provided at both ends of the adjacent sides of the two stops. After the bolts are sequentially inserted into the corresponding mounting through holes, they are engaged with nuts to lock the two stops together and fix them on the tool spindle.

[0015] According to some embodiments of the present invention, there is a gap between the ends of the two stops through which the same bolt passes, and the tightness of the two stops is achieved by rotating the bolt and the nut.

[0016] Because the present invention adopts the above technical solution, it has at least the following advantages:

[0017] 1. By having the end of the casing and the outer circumference of the tool mandrel respectively abut against the two ends of the straightening structure, the straightening structure can apply radial force to the tool mandrel in all circumferential directions during the process of changing from a horizontal to a vertical position or from a vertical to a horizontal position, so that the tool mandrel is kept in a non-biased state, that is, to achieve the anti-biasing effect of the tool mandrel during wellhead pre-connection.

[0018] Second, by preventing the tool spindle from being offset, the adverse effects of tool spindle offset on safety can be avoided, and the impact on tool seals can be reduced.

[0019] Third, the setting and disassembly of the straightening structure are achieved through the anti-drop structure. The straightening structure is set during the wellhead pre-connection process and reinforced by the anti-drop structure. After the wellhead pre-connection process is completed, the fixed state of the straightening structure is released, and the straightening structure can be removed. The operation is convenient and quick, and it can be reused.

[0020] Fourth, the tool spindle can be prevented from deflecting by the abutting action at both ends of the straightening structure. It takes advantage of the characteristics of the wellhead structure itself, and the structure is simple, reliable and has a long service life.

[0021] Fifth, because the anti-drop structure strengthens the stability of the straightening structure, it ensures sufficient stability of the straightening structure during wellhead casing offset, preventing the straightening structure from loosening due to drastic stress changes, thereby ensuring the safety of the tool mandrel and reducing the impact on the tool seal. Attached Figure Description

[0022] Figure 1 These are schematic diagrams of the tool mandrel anti-offset tool for wellhead pre-connection, as well as the wellhead casing and tool mandrel, according to some embodiments of the present invention.

[0023] Figure 2 This is a schematic diagram of the structure of the centering ring in the tool mandrel anti-offset tool for wellhead pre-connection according to some embodiments of the present invention;

[0024] Figure 3 This is a schematic diagram of the anti-drop structure in a tool mandrel anti-offset tool for wellhead pre-connection according to some embodiments of the present invention.

[0025] Marked in the attached diagram:

[0026] 100 is the straightening ring;

[0027] 110 is the inner ring body;

[0028] 120 is the stepped end face;

[0029] 130 is the protruding end;

[0030] 140 is the first step;

[0031] 150 is the second step;

[0032] 200 is a structure designed to prevent falling.

[0033] 210 is a stop block;

[0034] 220 is for bolts;

[0035] 300 is the wellhead casing;

[0036] 400 is the tool spindle. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0038] In the description of this invention, it should be noted that the terms "upper", "lower", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the system or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0039] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "assembly," "setup," and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0040] This invention provides a tool mandrel anti-offset tool for wellhead pre-connection, which aims to achieve the anti-offset effect of the tool mandrel during wellhead pre-connection by having the two ends of the straightening structure abut against the end pipe body of the wellhead casing and the outer circumferential surface of the tool mandrel respectively.

[0041] The tool mandrel anti-offset tool for wellhead pre-connection provided in the embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0042] Reference Figures 1 to 3As shown, according to some embodiments of the present invention, a tool mandrel 400 pre-attached to a wellhead is provided with an anti-offset tool, comprising: a straightening structure and an anti-drop structure 200. The straightening structure is detachably disposed between the end face of the wellhead casing 300 and the outer peripheral surface of the tool mandrel 400 inserted through the wellhead casing 300. The outer end of the straightening structure is adapted to abut against the end tube of the wellhead casing 300, and the inner end is adapted to abut against the outer peripheral surface of the tool mandrel 400 inserted inside the casing, so as to limit the tool mandrel 400 in the circumferential direction and prevent it from deviating radially. The anti-drop structure 200 is used to keep the straightening structure in a fixed state that limits the tool mandrel 400.

[0043] It should be noted that the straightening structure has a fixed state that limits the tool spindle 400 in the circumferential direction, and a loose state that allows the tool spindle 400 to be removed. The anti-drop structure 200 is used to fix the straightening structure and enhance its stability. When the anti-drop structure 200 releases its function of holding the straightening structure in the fixed state, the straightening structure can be removed from the tool spindle 400.

[0044] In the above embodiment, the two ends of the straightening structure abut against the end pipe of the wellhead casing 300 and the outer circumferential surface of the tool mandrel 400, respectively. During the process of changing from a horizontal position to a vertical position or from a vertical position to a horizontal position multiple times, the straightening structure can apply radial force to the tool mandrel 400 in all circumferential directions, so that the tool mandrel 400 is kept in a non-biased state, that is, it can achieve the anti-biasing effect of the tool mandrel 400 during wellhead pre-connection.

[0045] It is worth noting that, since the straightening structure is located between the end face of the wellhead casing 300 and the outer circumferential surface of the tool mandrel 400 through which the wellhead casing 300 is inserted, the straightening structure can be easily disassembled and assembled.

[0046] Furthermore, by preventing the tool spindle 400 from being offset, the present invention can avoid the adverse effects on the safety of the tool spindle 400 offset and reduce the impact on the tool seal.

[0047] In the above embodiments, the anti-drop structure 200 enables the setting and disassembly of the straightening structure. The straightening structure is set during the wellhead pre-connection process and reinforced by the anti-drop structure 200. After the wellhead pre-connection process is completed, the fixed state of the straightening structure is released, and the straightening structure can be removed. The operation is convenient and quick, and it can be reused.

[0048] Furthermore, since the present invention can prevent the tool spindle 400 from being offset by the abutting action at both ends of the straightening structure, it utilizes the inherent characteristics of the wellhead structure and thus has beneficial effects such as simple and reliable structure.

[0049] Furthermore, since the anti-drop structure 200 strengthens the stability of the straightening structure, it can ensure that the straightening structure has sufficient stability during the offset of the wellhead casing 300, avoiding the straightening structure from loosening due to drastic changes in force, thereby ensuring the safety of the tool mandrel 400 and reducing the impact on the tool seal.

[0050] Optionally, refer to Figure 1 and Figure 2 As shown, in some embodiments, the straightening structure is configured as a straightening ring 100, the inner end of the straightening ring 100 is configured as an inner ring body 110 that abuts against the outer peripheral surface of the tool mandrel 400, and the outer end of the straightening ring 100 and the end cylinder of the wellhead casing 300 are configured as a stepped end face 120 and the other is configured as a straight cylinder to achieve interlocking.

[0051] More specifically, the inner ring 110 surrounds the outer circumferential surface of the tool mandrel 400 and is adapted to abut against the outer circumferential surface of the tool mandrel 400 for limiting. The straightening structure and the end cylinder of the wellhead casing 300 are engaged by a stepped end face structure, which facilitates disassembly and assembly. The stepped end face 120 structure can also realize the mutual limiting effect of the straightening ring 100 and the wellhead casing 300 in the axial direction.

[0052] However, this design is not limited to this. In other embodiments, the centralizing ring 100 and the end cylinder of the wellhead casing 300 can also be connected by means such as threaded connection, without any particular limitation.

[0053] Optionally, refer to Figure 1 and Figure 2 As shown, in some embodiments, the end tube of the wellhead casing 300 is cylindrical; the outer end of the centralizing ring 100 is provided with a stepped end face 120 adapted to engage with the end tube of the wellhead casing 300. The stepped end face 120 includes a first stepped portion 140 adapted to abut against the inner wall of the wellhead casing 300, and a second stepped portion 150 adapted to abut against the end face of the wellhead casing 300. In this way, the centralizing ring 100 can be adapted to most wellhead casings 300 that are cylindrical, and it can be universally applied to various operating scenarios.

[0054] More specifically, during installation, the first step 140 can be inserted into the wellhead casing 300 and abut against the inner wall of the wellhead casing 300, while the second step 150 is exposed outside the end face of the wellhead casing 300 and abuts against it. The straightening structure is then fixed by the anti-fall structure 200.

[0055] Optionally, refer to Figure 1 and Figure 2As shown, in some embodiments, the length of the first stepped portion 140 along the axial direction of the wellhead casing 300 is greater than the length of the second stepped portion 150 along the axial direction of the wellhead casing 300. Understandably, since the straightening structure is used to prevent the tool mandrel 400 from shifting, the contact between the first stepped portion 140 and the inner wall of the wellhead casing 300 is preferred, so the first stepped portion 140 is preferably configured to have a sufficient bearing area.

[0056] Optionally, refer to Figure 1 and Figure 2 As shown, in some embodiments, the centralizing ring 100 includes a first part and a second part located on opposite sides of the tool mandrel 400. The inner ends of the first part and the second part are joined to form an inner ring body 110, and both outer ends are provided with stepped end faces 120. The first part and the second part can be confined to the inner wall surface of the wellhead casing 300 and the outer peripheral surface of the tool mandrel 400. In this way, the centralizing ring 100 can be installed by joining the first part and the second part, and the centralizing ring 100 can be removed by separating the first part and the second part. The operation is simple and easy, especially when the tool mandrel 400 is long or other situations make it difficult to fit the centralizing ring 100 onto the outer peripheral surface of the tool mandrel 400. The split design of the centralizing ring 100 is particularly convenient for disassembly and assembly.

[0057] However, this design is not limited to this. In other embodiments, the straightening ring 100 may also be composed of multiple parts similar to the first and second parts described above, such as three.

[0058] Optionally, refer to Figure 1 and Figure 2 As shown, in some embodiments, the inner ends of the first and second parts are configured as semicircular rings suitable for engaging the outer peripheral surface of the tool mandrel 400, or have two abutting planes capable of forming an included angle, the included angle facing the outer peripheral surface of the tool mandrel 400 and selected from the range [20°, 160°], that is, the included angle can be 20°, 30°, 40°, 50°, 60°, 70°, 80°, 90°, 100°, 110°, 120°, 130°, 140°, 150°, 160° or other values ​​from 20° to 160°.

[0059] Optionally, refer to Figure 1 and Figure 2 As shown, in some embodiments, the first part and the second part are symmetrically arranged, and each part is provided with two protruding ends 130 extending outward at intervals. The outer ends of the protruding ends 130 are provided with stepped end faces 120. A space is formed between the protruding ends 130 of the straightening ring 100, which can reduce the weight of the straightening ring and save materials.

[0060] Optionally, refer to Figure 1 and Figure 2As shown, in some embodiments, the four protruding ends 130 are distributed at 90-degree intervals in pairs along the circumference of the inner ring body 110. In this way, the interaction force between the centralizing ring 100 and the wellhead casing 300 can be kept balanced, without being too concentrated in one direction, and the centralizing ring 100 can provide sufficient support to prevent the tool mandrel 400 from being deflected in any direction of the wellhead casing 300.

[0061] Optionally, refer to Figure 1 and Figure 2 As shown, in some embodiments, the anti-drop structure 200 is detachably mounted on the tool mandrel 400 on the side of the straightening structure opposite to the wellhead casing 300, for axially abutting against the limiting straightening structure on the tool mandrel 400. In this way, the outer end of the straightening ring 100 is provided with a stepped end face 120 and receives a force from the end face of the wellhead casing 300 toward the anti-drop structure 200. The anti-drop structure 200 applies a reverse force to the straightening structure, thereby ensuring the force balance of the straightening ring 100. Furthermore, the anti-drop structure 200 being mounted on the tool mandrel 400 on the side of the straightening structure opposite to the wellhead casing 300 facilitates its assembly and disassembly by the operator.

[0062] However, this design is not limited to this. In other embodiments, the anti-fall structure 200 may also be located at, for example, the outer edge of the wellhead casing 300.

[0063] Optionally, refer to Figure 1 and Figure 3 As shown, in some embodiments, the anti-drop 200 includes two interlocking stops 210, which are detachably mounted on a tool mandrel 400 on the side of the straightening structure opposite to the wellhead casing 300 via bolts. However, this design is not limited to this; in other embodiments, the stops may be, for example, a single stop.

[0064] Optionally, refer to Figure 1 and Figure 3 As shown, in some embodiments, the middle of the adjacent sides of the two stops 210 is provided as an arc-shaped surface that adapts to the outer peripheral surface of the tool spindle 400. Corresponding mounting through holes are provided at both ends of the adjacent sides of the two stops 210. Bolts 220 are sequentially inserted through the corresponding mounting through holes and, in conjunction with nuts, lock the two stops 210 together and fix them to the tool spindle 400. Thus, by rotating the nut and bolts 220, the two stops 210 can be connected and disassembled, which also allows for the assembly and disassembly of the anti-drop structure 200. It can be understood that by tightening the stops 210 with bolts 220 and nuts, the tool spindle 400 is locked by friction, thereby preventing the centering ring 100 from falling out of the sleeve.

[0065] However, this design is not limited to this. In other embodiments, the two stops 210 can also be hinged at one end and have corresponding mounting through holes at the other end. The two stops 210 can be connected by bolts 220 and nuts.

[0066] In some other embodiments, the stop 210 is provided as, for example, one, and the stop 210 may be directly screwed onto the tool spindle 400 by screws.

[0067] Without loss of generality, refer to Figure 1 and Figure 3 As shown, in some embodiments, there is a gap between the ends of the two stops 210 through which the same bolt 220 passes, and the two stops 210 are tightened or loosened by rotating the bolt 220 and the nut. That is, by rotating the bolt 220 and the nut, the two stops 210 are brought closer or further apart, thereby clamping or loosening the tool spindle 400.

[0068] It should be noted that the "and / or" in the text includes three options. Taking "A and / or B" as an example, it includes technical option A, technical option B, and technical option that satisfies both A and B.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A tool mandrel anti- deflection tool for wellhead pre- make-up, characterized by, Comprising: a righting structure, detachably arranged between the end face of the wellhead casing and the outer circumferential surface of the tool mandrel passing through the wellhead casing, the outer end of the righting structure being adapted to abut the end pipe body of the wellhead casing, and the inner end being adapted to abut the outer circumferential surface of the tool mandrel passing through the casing, so as to limit the tool mandrel in the circumferential direction and prevent it from deviating in the radial direction; and an anti-falling structure for keeping the righting structure in a fixed state of limiting the tool mandrel; the righting structure is configured as a righting ring, the inner end of the righting ring being provided as an inner ring body abutting the outer circumferential surface of the tool mandrel, and the outer end of the righting ring being provided as a stepped end face with one of the end cylindrical body of the wellhead casing being a stepped end face and the other being a straight cylinder to realize engagement; the end cylindrical body of the wellhead casing is provided as a straight cylinder; the outer end of the righting ring is provided as a stepped end face adapted to engage with the end pipe body of the wellhead casing, the stepped end face comprising a first stepped portion adapted to abut the inner side wall surface of the wellhead casing and a second stepped portion adapted to abut the end face of the wellhead casing; the righting ring comprises a first portion and a second portion located in opposite directions of the tool mandrel respectively, the inner end of the first portion and the inner end of the second portion are spliced to form the inner ring body, and the outer end of each is provided with the stepped end face.

2. The tool mandrel anti-deviation tool for wellhead pre-connection according to claim 1, wherein the length of the first stepped portion along the axial direction of the wellhead casing is greater than the length of the second stepped portion along the axial direction of the wellhead casing; and / or the inner end of the first portion and the second portion is provided as a semicircular ring adapted to engage the outer circumferential surface of the tool mandrel, or has two abutting planes capable of forming an included angle, the included angle being towards the outer circumferential surface of the tool mandrel and selected from the range [20°, 160°].

3. The tool mandrel anti-deviation tool for wellhead pre-connection according to claim 1, wherein the first portion and the second portion are symmetrically arranged, and each is provided with two outwardly extending protruding ends, the outer end of the protruding end is provided with the stepped end face, and the four protruding ends are distributed at an interval of 90 degrees along the circumferential direction of the inner ring body.

4. The tool mandrel anti-deviation tool for wellhead pre-connection according to any one of claims 1 to 3, wherein the anti-falling structure is detachably arranged on the tool mandrel on the side away from the wellhead casing of the righting structure, so as to abut and limit the righting structure in the axial direction of the tool mandrel.

5. The tool mandrel anti-deviation tool for wellhead pre-connection according to claim 4, wherein the anti-falling structure comprises two spliced stop blocks, and the two stop blocks are detachably arranged on the tool mandrel on the side away from the wellhead casing of the righting structure by a bolt structure.

6. The tool mandrel anti-deviation tool for wellhead pre-connection according to claim 5, wherein The arc-shaped surface is arranged at the middle of the two adjacent sides of the stop block, and the corresponding mounting through holes are arranged at the two ends of the two adjacent sides of the stop block. The two stop blocks are fixed on the tool mandrel by screwing the nuts after the bolts pass through the corresponding mounting through holes.

7. The tool mandrel anti-offset tool for wellhead pre-connection of claim 6, wherein, The two stop blocks have a space between the ends for the same bolt to pass through, and the tightness of the two stop blocks is realized by rotating the bolt and the nut.

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